10 Tips
Your motocross clutch is the key to your bike's performance, and by
extension, yours. You might have more tricks up your sleeve than anyone else hitting the dirt but if your clutch isn't
up to par, you and your engine are going to be on totally different wavelengths and no translator out there can help. Let's
talk about how to put the clinch on your clutch.
First, Get Rid of those Factory Clutch Springs!
Bike factories take a minimalist view when they assemble the clutch assembly.
One of the reasons they do this is to not turn off weaker riders in the showroom. They want all prospective buyers to say,
"Ahhh," and not, "Arrgh!"
So if
you're not comfortable with wimpy clutch action (and really, who is?), go ahead and swap them out the springs for stiffer
ones. For instance, you can substitute 250-rated springs if you're a 125 jockey.
For fine-tuning, keep in mind that you don't have to change them all out; in most cases two or three will do
– just experiment and see what works for you.
Secondly, Don't Neglect Your Tranny Oil
No, this isn't like your car or truck, where you only change it every year, or in some cases, hardly ever. Ideally,
replace your tranny oil every two or three races. Sound excessive? Maybe, but it's cheaper than a tranny overhaul, and
the crud you pick up on the track will place early stress on your clutch plates.
Third, Carry Shims for a Quick Fix
Suppose you're out at the moto and halfway through the day, your clutch starts feeling spongy and you're
fresh out of springs. What to do? If you packed a mess of assorted washers, you can simply insert the right ones under the
bolt and viola! The added thickness will preload your springs and you're back on your game.
Forth, Remember that in a Pinch You can Run Automatic Transmission
Fluid
Although you might not have known it,
you can top off your tranny to the proper level with automatic tranny fluid. If you have to though, be sure to use ATF (GM
compatible), but don't use Ford type fluid. (The container will tell you which it is.)
What's the difference? GM fluid grips better than Ford fluid, which is slick as molasses. Which you don't
want in a moto.
Fifth,
Don't Use Factory-Installed Aluminium Clutch Plates
Sure, they're bright and shiny, and work just fine for road touring bikes, but they're not tough enough for
extended motocross use. For one thing, they don't hold up as well as steel plates, which are heavier, but more durable.
The drawbacks of aluminium are two-fold: fist, since
they wear more quickly than steel, they leave metallic deposits in the oil, which hastens mechanical wear. Secondly, aluminium
warps easily when subjected to the high heat generated during a moto.
Sixth, Resurface Ageing Clutch Plates
There's no sense in buying new plates before you have to. As the plates begin to age, they build up a glaze layer
on the surface which makes them slip more noticeably.
When
you begin to notice this slippage, bring the plates back to life by taking out your fiber clutch plates and use a sanding
block to remove the slippery glaze. Once you notice the glaze gone, clean them well and reinstall them.
Seventh, Don't Set your Clutch Lever too
Tight
Don't make the common
mistake of adjusting your clutch lever too snug. If you do this, you're just asking for trouble. It should have a wee
bit of play in it. How much? No need to get too technical. Just set it so that a quarter will slide between the lever perch
and the lever without the
clutch cable being taught.
If you're a bit low on funds and don't have a quarter on hand, just use your house key!
Eighth, How to Care for Your Clutch Basket
Have you ever wondered how your clutch
plates operate when the case is sealed and you can't see the action? There's an aluminium basket in there with just
short of a dozen tangs. These tangs are what your clutch plates slide up and down on. As you can imagine, there's quite
a bit of wear and tear going on there in the heat of moto battle.
In particular, it wears notches in the tongs. The end result of this is that the notches get in the way of clutch
plate movement. To maximize the lifetime of both the basket and the plates, use a file to take the notches out. Of course,
by doing this, you're contributing to the wear and tear because the plate movement gets sloppier, but extending the life
of the basket and plate is worth it.
Ninth, Sooner or Later You'll Need new Plates
Clutch plate life, like all good things, eventually comes to an end.
How can you tell when it's time to retire them? Measure the thickness. You can ask your dealer or consult your
user's manual for the proper specs. If they're too thin, change 'em out!
And Tenth,
Give Yourself the Gift that Keeps on Giving
Nothing says quality to a moto aficionado like a Hinson clutch basket. It just doesn't get any better. They also
make clutch hubs and plates if you want to go for the whole enchilada.
But
what makes the Hinson basket so good? Engineering, in a nutshell. Hinson takes the next step in extending clutch plate life
while dissipating friction heat by providing windows through which the oil is forced. Read more about Hinson at http://www.hinsonracing.com/main.html.